Feedback Drive

Here is an update on the new code library for OpenDrop implementing the feedback drive. I made good progress as you can see in the video. The feedback circuit, reads all 128 electrodes to memory in 10-20 ms allowing real-time asynchronous feedback drive.

The feedback reading allows for:
– Know where droplets are
– Auto find/initialization of Dropplets
– Drive at optimum speed, flow-like driving
– Compensate for bad electrodes, slow movement, lazy droplets, prevent from loosing droplets
– Prevent collision, unwanted mixtures of droplets
– Error correction
– Measure size/volume of droplet
– Measure Mixture


Technical Details:

ETFE foil, on carrier, 12.5um thick
fluor polymer coating 100ul, (Fluoropel from Cytonix)
Spinncoated for 20sec and cured at 150deg
ITO glass also coated with fluoropel
Grounding with cooper wire
sikicon oil no.5 between foil and electrodes

Water with ink
Volume 1-2ul
Distance 150-200um

Voltage 250VDC

OpenDrop V2.1:
– 120 electrodes
– Arduino micro
– Oled display
– Integrated high voltage supply
– Feedback amplifier

See also OpenDrop V2.1 here.